The present technology relates to a decoding device, a decoding method, and a program. Especially, the present technology relates to a decoding device, a decoding method, and a program that can reduce an operation amount in inverse orthogonal transform with respect to a frequency signal including a narrowband signal and a wideband signal.
In the related art, there is an encoding device that transforms a time signal of a sound or the like into a frequency signal and quantizes the frequency signal so as to encode and transmit the signal. Further, there is a decoding device that decodes encoded data which is transmitted by such encoding device and inversely quantizes the data so as to transform the resulting frequency signal into a time signal.
In such decoding device, inverse orthogonal transforms such as inverse fast Fourier transform (IFFT), inverse discrete cosine transform (IDCT), and inverse modified discrete cosine transform (IMDCT) are often used as the transform of a frequency signal into a time signal (referred to below as frequency-time transform).
On the other hand, there is a radio communication device that is provided with a fast Fourier transform (FFT) having a predetermined demodulation property and an FFT which has an inferior demodulation property but exhibits low power consumption and that switches and uses these FFTs so as to suppress power consumption (For example, Japanese Unexamined Patent Application Publication No. 2008-258992).